I use a chunk of heavy (10mm) thick steel, about 70mm diameter. I use a cheap thermocouple temp meter to measure the metal chunk. I use the small gas burner on the kitchen stove. I get the metal up to 150 deg C.
And honestly that is the answer. Practice Practice Pratice. Also if it is now happening for you watch a few other channels videos, sometimes one method just suits you best
My pre-heater is a 12x7cm PTC heating element. It goes to a fixed temperature (and thus can never overheat the board). And it cost a whopping 4 Euro from China (delivered).
My heat gun has a nozzle that directs the air sideways. So I'm trying to make a holder to put a board next to it. It should work really well once I cobble something together.
Good video. I had a job interview years ago at an electronics manufacturing plant and was asked what is one of the worst packages to work with. We said QFN at the same time.
TBH QFN takes a bit of time to master. But once you do then it is pretty easy. The main thing IMHO is getting some scrap boards and getting the 'feel' for the way the surface tnsion of the solder works to help you. Once you learn how it is going to behave the rest will just happen
I struggled with this for 6 hours and inhaled flux fumes because I watched a tutorial on the internet. And I put too little solder under the middle soldering pad of the qfn chip. Because of this, the chip did not want to float and did not want to position itself.
With no visible pins I thought soldering these by hand would be near impossible, but using plenty of flux and a fine tipped bit I did a number of these packages (new parts/PCBs) one contact at a time. Just run the tinned tip up the pad to the package and the solder will magically wicks itself underneath. A stereo microscope with plenty of working distance (so you can tilt the board and come at it from the side) helps an awful lot. Next time I'll give the drag soldering a go.
@@modorangeorge4991 I hear you. No way to ensure getting the flux out from under the package after soldering. I know it's no-clean, but still bothers me a bit.
Hi Rich, great video. I have a question for you ( I am new to this soldering stuff ) Once you solder the chip on , should I re-flow a second time and squeeze the chip down with some tweezers? I seen a few videos that suggested that but I have no idea if that's BS or what. Thanks very much. Love your videos man, your right down to earth
There are a few methods, personally I look for the component 'floating' on the solder and then I know I have it. But I would suggest try other methods too and find something that works for you
I saw a video on tiktok showing a 7805 regulater metal bit up, as a tiny heat pad. I believe they connected 5 volts to the output!, it drew 1 amp. I've not tried it myself yet., but could work?
You know, I talk to so many companies, pro audio mainly that have been switching fully over the last decade to SMC from Through Hole designs, and so many of them get defensive at the mention of SMC, and just yell at you, and say what's wrong with SMC, it's better. The main issue for me, it's not even like I'm talking about the sound, even though that is a topic as well, but I'm not even saying like "oh through hole sounds so much better, but for me it's mainly the fact that being able to fix, repair, maintain, mod etc, a unit yourself, or even by a lot of tech's goes out the window, and another thing is getting proper schematics for SMC design's is not really possible, not to mention the companies don't release them anymore. Basically they don't want you to be able to work on your own unit, and want you to have no other choice, but to send it to them, in which case even the company isn't going to replace single components, they will just replace the board(s). I know that working on SMC stuff is totally possible, and it's own skill in itself, but I'm just saying, even for the average guy like me who knows how to fix/maintain through hole gear to a certain extent, working on any type of SMC stuff seems almost impossible at the moment, and even if I felt I had.a grasp on it, it's more like if I had a $6000 piece of equipment that's SMC, I would be afraid to touch it, and I'm guessing a lot of people would. My main point here is, it's fine if the company is around, but what happens if they go out of business one day, and your gear breaks, and although there may be people out there who could possibly work on it, they will still be without a schematic, and maybe even to nervous to do it if it's expensive gear, but it's good that it's still possible, and people out there learning to work on SMC stuff, even though I don't think the companies ever cared iff it could be fixed at all, and that's sort of my main point.
This is why you need to get some scrap boards (doesn't matter what they are even if not audio related) and practice removind and rsoldering things like QFN. I can guarantee once you understand the way the chip reacts due to flux and solder surface tension it will be like a revelation! It's just like riding a bike, once you get the feel for it then it is so easy you don't even think about it. In the same way the gyroscopic effect of the spinning wheels on a bike balences it for you.
@@LearnElectronicsRepair Ya, true, and I hear ya. Definitely a good skill to learn aside from Through Hole soldering, but right now it still seems scary, the thought of working on a $2000-7000 piece of SMC Audio Gear haha. So what do you mean when you say QFN? When I say SMC I just mean Surface Mount Components.
@@jamescassidy4045 Well there are SMD/SMC and then there are QFN (Aand for that matter BGA) The reason this is scary is exactly what youy say - the thought of working on expensive equipment. Get some scap stuff and practice, no fear just get a feel for how the flux and solder behave. Then you can work on the expensive stuff with a lot od confidence
It's hard to believe but we used to get books called Riders Manuals that were updated every year and contained schematics of all commercial radios ever produced! These books are still being used today by antique radio enthusiasts to repair antique radios and to replicate or study those circuits. Too bad this practice of making circuit diagrams available isn't common anymore.
@@68HC060 Yes, when i originally recorded the video I had a segment where I looked at the job under the microscope before drag soldering down the sides of the QFN, talked about it and then did the drag soldering. I then recorded the next segment where I look under the microscope after drag soldering. When I came to edit the segments together I found that the first of these segments had not recorded. Sometimes OBS does this, I end up with a very short clip of video less than one second long, and it's really annoying. So at that time I stopped editing and next morning re-recorded the segment from 17:24 to 18:53. At that time I also recorded a new segment from 18:53 to 21:06 as I realised during the first edit that the video as a whole would be improved if I showed and discussed the equipment and settings I was using. From 21:09 is after I did the drag solder segment the second time as during the first time I was talking about 'now lets look at the results again' which was no longer relevant so I couldn't use that. Since the topic of this video is how to solder QFN I didn't think that if a nearby capacitor moved it would be relevant to the completed video hence it is what it is. The other option would have been to re-record the whole video as I couldn't unflow the QFN to record that lost part with the initial inspection again. I hope that explains the mystery, and well spotted 🙂 Let's call it the magic of television.
@@LearnElectronicsRepair :smiley: - Persoally, I don't think it's relevant whether or not the capacitor moved - as you say, the video is about the QFN. But it teaches us to keep an eye on the nearby components. 😉
When did all components become a lot more heat tolerant ? LOL... have they??? Practice indeed! I've been doing so +50 years, fiddling as a kid and then master trade qualified. #2 need is a microscope and quality tools.
Yes, that'll work just fine - you can also get a smaller one for travelling, some of those fold and can lay down flat on the table. As I mentioned elsewhere, the heating element from a coffee maker will also do; it'll stay below 100 degree Celsius.
If you have loads of money and want an easier way to solder/desolder QFN and BGA, then you could get an IR station. -Still you'll need to practise before doing any real work.
It would be nice if one of the brands would send me one to review 😉 I don't generally use my BGA rework station on video as it is a really expensive one, three zone Hot Air with IR preheater, optical BGA alignment and Semi Automatic operation. It's not really not relevant to the viewers here but an IR rework station would be of interest to many. Any particular one you would recommend? These things are not cheap but the more 'affordable' the better.
@@LearnElectronicsRepair - Unfortunately I only tried one once (on a soldering course), but I forgot the name of it. What I do remember, is that it was very easy to use. So if one needs a high success-rate and do not have much time for the soldering/desoldering process, it would pay to have one. -If you were to make a business upgrading Raspberry Pi 4B from 1GB to 8GB RAM, you'd definitely want one of those. 😉 (I think the Raspi 3 could probably also be upgraded to at least a couple of GB, but that's another story)
I am sorry for incovinience, if you live in the America, American manufacturers dont't produce even temperature measurer at motherland? Or Chinese goods cheaper?
Heya, yes nice soldering and desoldering video wih lot and lots of tippical and practical tips
I use a chunk of heavy (10mm) thick steel, about 70mm diameter. I use a cheap thermocouple temp meter to measure the metal chunk. I use the small gas burner on the kitchen stove. I get the metal up to 150 deg C.
I use the heated bed on my 3D printer but keep meaning to get an old clothes iron to make a board heater for when i have a print running.
Great Video and useful to me. Got some of the kit, but not used it much yet. Need to find some scrap boards to practice on.
And honestly that is the answer. Practice Practice Pratice. Also if it is now happening for you watch a few other channels videos, sometimes one method just suits you best
My pre-heater is a 12x7cm PTC heating element. It goes to a fixed temperature (and thus can never overheat the board). And it cost a whopping 4 Euro from China (delivered).
Never underestimate the heating plate from a coffee machine. 😃
Fantastic.
My heat gun has a nozzle that directs the air sideways.
So I'm trying to make a holder to put a board next to it.
It should work really well once I cobble something together.
Good video. I had a job interview years ago at an electronics manufacturing plant and was asked what is one of the worst packages to work with. We said QFN at the same time.
TBH QFN takes a bit of time to master. But once you do then it is pretty easy. The main thing IMHO is getting some scrap boards and getting the 'feel' for the way the surface tnsion of the solder works to help you. Once you learn how it is going to behave the rest will just happen
I struggled with this for 6 hours and inhaled flux fumes because I watched a tutorial on the internet. And I put too little solder under the middle soldering pad of the qfn chip. Because of this, the chip did not want to float and did not want to position itself.
Push the chip after it reubicates that will join the middle part with the outside and use tweezers move the chip
With no visible pins I thought soldering these by hand would be near impossible, but using plenty of flux and a fine tipped bit I did a number of these packages (new parts/PCBs) one contact at a time. Just run the tinned tip up the pad to the package and the solder will magically wicks itself underneath. A stereo microscope with plenty of working distance (so you can tilt the board and come at it from the side) helps an awful lot. Next time I'll give the drag soldering a go.
Usually I solder these without cleaning the pads or using any flux, it works almost every time. If you clean the pads you have more work to do.
@@modorangeorge4991 I hear you. No way to ensure getting the flux out from under the package after soldering. I know it's no-clean, but still bothers me a bit.
Great video, thanks for spending the time creating it. Just wondering if you will finish the bga rework tutorial series you published last year?
Actually I was just thinking about that yesterday 😉
you missed the obvious hot plate - a clothes iron, but a pig to hold unless you have a couple of spare bricks
Hi Rich, great video. I have a question for you ( I am new to this soldering stuff ) Once you solder the chip on , should I re-flow a second time and squeeze the chip down with some tweezers? I seen a few videos that suggested that but I have no idea if that's BS or what. Thanks very much. Love your videos man, your right down to earth
There are a few methods, personally I look for the component 'floating' on the solder and then I know I have it. But I would suggest try other methods too and find something that works for you
@@LearnElectronicsRepair Thanks ever so much for taking the time to reply, much appreciated. Your a real gentleman and a scholar
I saw a video on tiktok showing a 7805 regulater metal bit up, as a tiny heat pad. I believe they connected 5 volts to the output!, it drew 1 amp. I've not tried it myself yet., but could work?
You know, I talk to so many companies, pro audio mainly that have been switching fully over the last decade to SMC from Through Hole designs, and so many of them get defensive at the mention of SMC, and just yell at you, and say what's wrong with SMC, it's better.
The main issue for me, it's not even like I'm talking about the sound, even though that is a topic as well, but I'm not even saying like "oh through hole sounds so much better, but for me it's mainly the fact that being able to fix, repair, maintain, mod etc, a unit yourself, or even by a lot of tech's goes out the window, and another thing is getting proper schematics for SMC design's is not really possible, not to mention the companies don't release them anymore. Basically they don't want you to be able to work on your own unit, and want you to have no other choice, but to send it to them, in which case even the company isn't going to replace single components, they will just replace the board(s).
I know that working on SMC stuff is totally possible, and it's own skill in itself, but I'm just saying, even for the average guy like me who knows how to fix/maintain through hole gear to a certain extent, working on any type of SMC stuff seems almost impossible at the moment, and even if I felt I had.a grasp on it, it's more like if I had a $6000 piece of equipment that's SMC, I would be afraid to touch it, and I'm guessing a lot of people would.
My main point here is, it's fine if the company is around, but what happens if they go out of business one day, and your gear breaks, and although there may be people out there who could possibly work on it, they will still be without a schematic, and maybe even to nervous to do it if it's expensive gear, but it's good that it's still possible, and people out there learning to work on SMC stuff, even though I don't think the companies ever cared iff it could be fixed at all, and that's sort of my main point.
This is why you need to get some scrap boards (doesn't matter what they are even if not audio related) and practice removind and rsoldering things like QFN. I can guarantee once you understand the way the chip reacts due to flux and solder surface tension it will be like a revelation! It's just like riding a bike, once you get the feel for it then it is so easy you don't even think about it. In the same way the gyroscopic effect of the spinning wheels on a bike balences it for you.
@@LearnElectronicsRepair Ya, true, and I hear ya. Definitely a good skill to learn aside from Through Hole soldering, but right now it still seems scary, the thought of working on a $2000-7000 piece of SMC Audio Gear haha. So what do you mean when you say QFN? When I say SMC I just mean Surface Mount Components.
@@jamescassidy4045 Well there are SMD/SMC and then there are QFN (Aand for that matter BGA) The reason this is scary is exactly what youy say - the thought of working on expensive equipment. Get some scap stuff and practice, no fear just get a feel for how the flux and solder behave. Then you can work on the expensive stuff with a lot od confidence
@@LearnElectronicsRepair OK thanks man!
It's hard to believe but we used to get books called Riders Manuals that were updated every year and contained schematics of all commercial radios ever produced! These books are still being used today by antique radio enthusiasts to repair antique radios and to replicate or study those circuits.
Too bad this practice of making circuit diagrams available isn't common anymore.
Some of the caps got knocked sideways....c148 and c154....
Great video, btw.
Those Caps were that way from the start.
Yes, but this was corrected (but correction didn't seem to be recorded).
@@68HC060 Yes, when i originally recorded the video I had a segment where I looked at the job under the microscope before drag soldering down the sides of the QFN, talked about it and then did the drag soldering. I then recorded the next segment where I look under the microscope after drag soldering. When I came to edit the segments together I found that the first of these segments had not recorded. Sometimes OBS does this, I end up with a very short clip of video less than one second long, and it's really annoying.
So at that time I stopped editing and next morning re-recorded the segment from 17:24 to 18:53. At that time I also recorded a new segment from 18:53 to 21:06 as I realised during the first edit that the video as a whole would be improved if I showed and discussed the equipment and settings I was using. From 21:09 is after I did the drag solder segment the second time as during the first time I was talking about 'now lets look at the results again' which was no longer relevant so I couldn't use that.
Since the topic of this video is how to solder QFN I didn't think that if a nearby capacitor moved it would be relevant to the completed video hence it is what it is. The other option would have been to re-record the whole video as I couldn't unflow the QFN to record that lost part with the initial inspection again. I hope that explains the mystery, and well spotted 🙂 Let's call it the magic of television.
@@LearnElectronicsRepair :smiley: - Persoally, I don't think it's relevant whether or not the capacitor moved - as you say, the video is about the QFN.
But it teaches us to keep an eye on the nearby components. 😉
Kids, Richard said "Anything to warm it up" but the answer is NO, you cannot use the Microwave oven. ;-)
Ah yeah I didn't think of that 😅
@@LearnElectronicsRepair I bet that some Brainiac would try it.
When did all components become a lot more heat tolerant ? LOL... have they???
Practice indeed! I've been doing so +50 years, fiddling as a kid and then master trade qualified.
#2 need is a microscope and quality tools.
Yeah modern SMD are definitely more heat tolerant than 1970s components for example. As are the PCBs themselves
What's up with C148, C154?
Clothes iron, upside down
😂 It Is like kill a mosquito with a gun...
@@paolomonai9511 If that is all you have it is better than nothing.
Yes anything like that 🙂
Yes, that'll work just fine - you can also get a smaller one for travelling, some of those fold and can lay down flat on the table.
As I mentioned elsewhere, the heating element from a coffee maker will also do; it'll stay below 100 degree Celsius.
@@68HC060 Agreed
thank you grandpa
If you have loads of money and want an easier way to solder/desolder QFN and BGA, then you could get an IR station.
-Still you'll need to practise before doing any real work.
It would be nice if one of the brands would send me one to review 😉 I don't generally use my BGA rework station on video as it is a really expensive one, three zone Hot Air with IR preheater, optical BGA alignment and Semi Automatic operation. It's not really not relevant to the viewers here but an IR rework station would be of interest to many. Any particular one you would recommend? These things are not cheap but the more 'affordable' the better.
@@LearnElectronicsRepair - Unfortunately I only tried one once (on a soldering course), but I forgot the name of it.
What I do remember, is that it was very easy to use. So if one needs a high success-rate and do not have much time for the soldering/desoldering process, it would pay to have one.
-If you were to make a business upgrading Raspberry Pi 4B from 1GB to 8GB RAM, you'd definitely want one of those. 😉
(I think the Raspi 3 could probably also be upgraded to at least a couple of GB, but that's another story)
I am sorry for incovinience, if you live in the America, American manufacturers dont't produce even temperature measurer at motherland? Or Chinese goods cheaper?
first :)
Hi Richard 🤗🤗
Good work 👍👍👍👍
But, your C148 an C154 wants to fight each other🤣🤣 ..why😱😱🫣